Venetian blind



B. WALKER VENETIAN BLIND Oct. 30, 1951 Filed March 20, 1950 Patented Oct. 30, 1951 UNITED STATES PATENT OFFICE VENETIAN BLIND Brooks Walker, Piedmont, Calif. Application March 20, 1959; Serial No. 150,640

and plastic type ladder tapes, or other ladder tapes where the stiffness of the side members of the ladder tape offers some resistance'when the blind is lifted with the cords placed in the offset positions between the slats and the ladder tape as is shown in my issued Patent No. 2,200,349.

A further object of this invention is to provide means whereby when the lifting cords are placed at the outside of the side members of the ladder tape that the ladder tape and slats will remain in reasonably good alignment during the lifting operation by the use of guide rings or other suitable means for slidably securing the lifting cords at the side members of the ladder tapes so that the tension of the lifting members will keep the ladder tapes parallel and through the tongues, or other suitable means of attachment, keep the slats in line with the lifting cords during the lifting operation.

Another object of the invention is to provide means for securing the externally mounted lifting cords to the ladder tapes at such points in the ladder tapes as will offer the minimum resistance to the lifting cords when the blind is in the lowered position and, also, when it is being raised with the tapes folded in a conventional manner with one loop of the tape folding out, two slats next to each other, and a fold of the side member between the next two slats, and then an outward fold with two more slats together, et cetera. If the ladder tape is secured to the lifting cord in the usual manner where the guide rings are located near the slats, the conventional folding of the ladder tape is materially interfered with and correct operation is not encountered.

Other objects of the invention will be more clearly pointed out in the accompanying drawing, specifications and claims.

I have illustrated my invention by way of example in the accompanying drawing, in which:

Figure 1 is a side elevation of a Venetian blind incorporating one form of the invention.

Figure 2 is a top view of the head rail shown in Figure 1.

Figure 3 is a View of an intermediate slat and associated tapes and lifting cord taken as a top view of one of the slats as illustrated in Figure 1.

Figure 4 is a partial view partly cut away showing a section of the ladder tape, lifting cords, and a slat taken from a portion of the left-hand ladder tape and one of the slats from Figure 1.

Figure 5 is a cut-away section showing a portion of a blind taken at or near the right-hand ladder tape looking end on as the ladder tape is folded for the raising of the bottom rail and collapsing of the slat spacing.

Figure 6 is an end view of a portion of the blind taken at section 5-5 of Figure 2, showing the relation of the lifting cords, the head rail, the tilt rail, and the uppermost slat with the upper portion of the ladder tape.

In all figures, like numerals of reference refer to the corresponding parts in various views.

In Figures 1 through 6, I have illustrated a Venetian blind having a head rail I0 which is preferably made of wood but could be constructed from the usual types of metal or closed head rails without departing from the scope of this invention. On the head rail is mounted a tilting mechanism I2 and a pivot support H which support the tilt rail IS in a manner so that it can be tilted by tilt cords I3 in a conventional manner. Ladder tapes 20 and 2| are suitably attached to the tilt rail l5, although they could be attached to mechanism inside of a metal head rail without departing from the scope of this invention. Lifting cords 30, 3|, 32, and 33 are located at the outside of the side members of the ladder tapes 20 and 2| respectively, as shown. These lifting cords 30, 3|, 32, and 33 are preferably fastened to the bottom rail I! as are the bottoms of the ladder tapes 2| and 20. The lifting cord 30 is guided on the room side of the ladder tape 20 by one or more guide rings such as are shown at 20a and 20b, and the other lifting cords are suitably guided by guide rings to I the ladder tape sides adjacent the respective lifting cords in a similar manner so that the sides of the ladder tapes and the slats 5 which are secured by tongues, or other suitably detachable means to the cross rungs, such as 2ld, are kept in substantial vertical alignment during the lifting operation of the blind.

It has been found by experiment that if the lifting cords are placed on the outside of the ladder tape side members and not between the staggered ladder rungs or between double ladder normal folding of the ladder tape as shown in Figure 5 where the location of the lifting cords and the guide rings are so located as to not interfere with the folding of the ladder tape. A plastic ladder tape, or other ladder tapes, in which the side members are inclined to be stiff as used in a Venetian blind construction, resistance to the proper accumulation of the slats during the lifting operation may result if the lifting cords go between the edges of the slats and the side members of the ladder tapes as shown in my Patent No. 2,200,349 which requires that the side members of the ladder tape fold outwardly (away from the lifting cord under tension) between each slat, whereas, the usual method when a route hole is used in the center, or when the lifting cords are at the outside of the ladder tapes is for the ladder tape to fold inwardly between two slats, and then outwardly around the next two slats, and then inwardly between two slats, et cetera, so that the location of a guide member between a certain two slats would not be desirable as that would be the place where the tape would ordinarily fold in between the slats, and if the ladder tape were guided at the slat station it would interfere with the outward folding of the ladder tapes.

The preferred construction as shown in this ap plication does not interfere with the normal folding of the ladder tapes as is shown in Figure 5 in particular, as well as in the other figures. The upper ends of the lifting cords 30, 3!, 32, and 33 preferably are spaced apart so that when the tilt rail is tilted into the vertical position, the lifting cords will be held fairly close to the side members of the tilt rail in this position. If a metal head rail were to be used, the pulleys or guides for the lifting cords would be at the outside of the ladder tapes near the drums which control the tilting of the ladder tapes rather than having the lifting cord pulleys inside of the side members of the ladder tape which is the usual method when lifting cords run through route holes in the slats or next to the edge of the slats and the side members of the ladder tapes. 7

I do not wish in any way to limit myself to the exact details or mode of operation set forth in the specification and drawings for it will be seen that wide departure may be made in the way of details without departing from the spirit and scope of my invention which is set forth in the following claims.

I claim as my invention:

1. 'In a Venetian blind having slats, ladder tapes, and at least two lifting cords for raising said blind, said lifting cords being located at the outside of the side members of said ladder tape, one at the front of the blind and another at the rear of the blind, said lifting cords being guided by members through which said lifting cords may slide, said members being located between said slat stations and attached to the side members of said ladder tape where the side members of said ladder tape fold outwardly away from said slats during the lifting operation.

2. In a Venetian blind having slats, a ladder tape for supporting said slats in spaced relationship, means for tilting said slats, at least two lifting cords for raising said blind, said lifting cords being located outside of the side members of each of two of said ladder tapes, one at the front of the blind and another at the rear of the blind, said ladder tapes folding in such'a way that the side members of said ladder tapes fold outwardly away from two slats which are together and inwardly between two slats and outwardly around two slats, et cetera, said lifting cords being guided in a slidable manner to said side members of said ladder tapes at a point where said ladder tape folds away from said slats when said blind is in the lifted position.

BROOKS WALKER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

